Multi-joint pectoral fin capable of efficiently reducing resistance
By designing the limiting mechanism and flexible plate structure of the multi-jointed pectoral fin, the problems of control complexity and increased power consumption during the movement of the robotic fish were solved, and efficient drag reduction and net thrust improvement were achieved.
Patent Information
- Application Number
- CN202422910769.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-11-27
AI Technical Summary
The pectoral fins of the robotic fish face problems of increased control complexity and power consumption during movement. Existing technologies increase the overall size, weight, and complexity to reduce the resistance of the recovery stroke.
A multi-jointed pectoral fin with high drag reduction is designed. Through the rotatable connection between the middle rigid plate and the front rigid plate, combined with the first and second limit mechanisms, the deformation of the flexible plate is utilized to maximize and minimize the pectoral fin area in the power stroke and recovery stroke respectively, to achieve efficient drag reduction.
The control complexity is simplified, and the overall size and weight of the robotic fish are reduced, while the net thrust is increased in one fin beat cycle, achieving efficient drag reduction.
Smart Images
Figure CN223355860U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of bionic robotic fish, in particular to a multi-jointed pectoral fin with high efficiency in drag reduction. Background Art
[0002] Pectoral fins play a vital role in the maneuverability and locomotion of fish and have become an important driving mechanism for robotic fish. In the paddling motion of the robotic fish's pectoral fins, the finbeat cycle involves a power stroke and a recovery stroke. To generate a greater net thrust during each paddling cycle, the pectoral fins must be braked differently during the power stroke and the recovery stroke. For example, the pectoral fins can be driven faster during the power stroke than during the recovery stroke. However, as the complexity of the motion increases, control becomes more complex and power consumption increases. Another approach is to equip an additional brake to reduce the effective area during the recovery stroke to reduce drag during the recovery stroke. However, this significantly increases the overall size, weight, and complexity of the pectoral fins and the robotic fish. Utility Model Content
[0003] In view of this, in order to solve the above-mentioned problems existing in the pectoral fin paddling motion of the robotic fish, an embodiment of the present invention provides a multi-jointed pectoral fin with high drag reduction.
[0004] The embodiment of the utility model provides a multi-jointed pectoral fin with high efficiency in drag reduction, comprising:
[0005] front rigid plate;
[0006] a middle rigid plate, the front portion of which is rotatably connected to the rear portion of the front rigid plate, and a first limiting mechanism is provided between the middle rigid plate and the front rigid plate to limit the middle rigid plate from rotating only in a predetermined direction of movement, and a first flexible plate is provided on the back of the middle rigid plate;
[0007] And two pectoral fin rigid plates are respectively connected to the upper and lower parts of the first flexible plate, and a second limiting mechanism is provided between the first flexible plate and the two pectoral fin rigid plates to limit the two pectoral fin rigid plates to move only in a predetermined direction of movement.
[0008] Furthermore, two ends of the front portion of the middle rigid plate are hingedly connected to two ends of the rear portion of the front rigid plate respectively.
[0009] Furthermore, two first hinge holes are provided at the front of the middle rigid plate, and two second hinge holes are provided at the rear of the front rigid plate. The two first hinge holes and the two second hinge holes correspond one to one and their axes coincide. The corresponding first hinge holes and second hinge holes are connected by a hinge pin.
[0010] Furthermore, the first limiting mechanism includes a limiting plate, which is fixed to the front surface of the front rigid plate and extends backward to the front surface of the rear portion of the middle rigid plate.
[0011] Furthermore, the middle rigid plate includes a vertical connecting plate and a horizontal connecting plate connected to each other, wherein the front side of the vertical connecting plate is rotatably connected to the rear side of the front rigid plate.
[0012] Furthermore, the middle portion of the first flexible plate is fixedly connected to the transverse connecting plate, and the upper and lower portions of the first flexible plate are respectively connected to the two pectoral fin rigid plates, so that two gaps are formed between the transverse connecting plate and the two pectoral fin rigid plates.
[0013] Furthermore, the second limiting mechanism includes a fixed limiting block and two movable limiting blocks, the fixed limiting block is fixed to the front side of the transverse connecting plate, the two movable limiting blocks are respectively fixed to the front sides of the two pectoral fin rigid plates, the top surface and bottom surface of the fixed limiting block are respectively in contact with the two movable limiting blocks, and the contact seam is located in the two gaps.
[0014] Furthermore, the fixed limiting block and the movable limiting block are both rectangular blocks, and the two movable limiting blocks are symmetrically arranged with respect to the fixed limiting block.
[0015] Furthermore, a second flexible plate is provided on the back side of the front rigid plate, and the second flexible plate is connected to the vertical connection plate.
[0016] Furthermore, the first flexible board and the second flexible board are both flexible films.
[0017] The beneficial effects brought about by the technical solution provided by the embodiment of the utility model are:
[0018] 1. The utility model provides a multi-joint pectoral fin with high efficiency and drag reduction, wherein a middle rigid plate is rotatably connected to a front rigid plate, and the middle rigid plate is connected to the pectoral fin rigid plate by a first flexible plate. During a power stroke, the two pectoral fin rigid plates cannot be bent or folded under the limiting action of a first limiting mechanism and a second limiting mechanism, and the pectoral fin area is maximized; during a recovery stroke, the limiting action of the first limiting mechanism and the second limiting mechanism disappears, and the first flexible plate produces an adaptive deformation, causing the two pectoral fin rigid plates to bend and fold to minimize the resistance on the pectoral fin, thereby achieving a highly efficient drag reduction effect, thereby increasing the net thrust during the flapping of the pectoral fin.
[0019] 2. The utility model has a multi-joint pectoral fin with high efficiency and drag reduction. Multiple joints of the pectoral fin can be controlled by a single motor drive, so that the pectoral fin can maintain the prescribed movement of the motor during the power stroke, so that the pectoral fin area is maximized. During the recovery stroke, the pectoral fin bends and folds to minimize the pectoral fin area, simplifying the control complexity and the overall size of the robotic fish. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a schematic diagram of the front of a multi-jointed pectoral fin with high efficiency and drag reduction according to the present invention;
[0021] Figure 2 This is a schematic diagram of the back of a multi-jointed pectoral fin with high efficiency and drag reduction according to the present invention;
[0022] Figure 3 This is an exploded view of a multi-jointed pectoral fin with high efficiency and drag reduction according to the utility model;
[0023] Figure 4 This is a motion diagram of a multi-jointed pectoral fin power stroke with high efficiency and drag reduction according to the present invention;
[0024] Figure 5 This is a schematic diagram of the state of the power stroke of a multi-jointed pectoral fin with high efficiency and drag reduction in the utility model;
[0025] Figure 6 This is a motion diagram of a multi-jointed pectoral fin recovery stroke with high drag reduction in the utility model;
[0026] Figure 7 It is a schematic diagram of the state of the recovery stroke of a multi-jointed pectoral fin with high efficiency in reducing drag according to the present invention.
[0027] In the figure: 1. Front rigid plate; 2. Middle rigid plate; 3. Pectoral fin rigid plate; 4. First limiting mechanism; 5. Second limiting mechanism; 6. Gap; 7. Connecting hole; 8. Second flexible plate; 9. Hinge pin; 10. First flexible plate; 11. First hinge hole; 12. Second hinge hole; 13. Vertical connecting plate; 14. Horizontal connecting plate; 15. Limiting plate; 16. Fixed limiting block; 17. Movable limiting block. DETAILED DESCRIPTION
[0028] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will further describe the embodiments of the present invention with reference to the accompanying drawings. The following describes a preferred embodiment of the present invention among multiple possible embodiments, which is intended to provide a basic understanding of the present invention, but is not intended to identify the key or decisive elements of the present invention or to limit the scope of protection to be provided.
[0029] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.
[0030] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.
[0031] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in the subsequent drawings. At the same time, it should be understood that for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual scale.
[0032] It should be noted that, unless otherwise specified or limited, the terms "mounted" and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.
[0033] Please refer to Figure 1 and 2 The present invention provides a multi-jointed pectoral fin with high drag reduction, which can be applied to a bionic robotic fish. The pectoral fin mainly includes a front rigid plate 1, a middle rigid plate 2, and two pectoral fin rigid plates 3. The overall shape of the multi-jointed pectoral fin with high drag reduction is similar to that of a fish's pelvic fin, for example, approximately fan-shaped.
[0034] The front rigid plate 1 is used to connect the body of the bionic robotic fish. As in this embodiment, the front end of the front rigid plate 1 is provided with a connecting hole 7, through which the front rigid plate 1 is mounted to the body of the fish.
[0035] Combine Figure 3 As shown, the front portion of the middle rigid plate 2 is rotatably connected to the rear portion of the front rigid plate 1, and a first limiting mechanism 4 is provided between the middle rigid plate 2 and the front rigid plate 1 to limit the middle rigid plate 2 from rotating only in a predetermined direction of movement, and a first flexible plate 10 is provided on the back of the middle rigid plate 2.
[0036] The two pectoral fin rigid plates 3 are respectively connected to the upper and lower parts of the first flexible plate 10, and a second limiting mechanism 5 is provided between the first flexible plate 10 and the two pectoral fin rigid plates 3 to limit the two pectoral fin rigid plates 3 to move only in a predetermined direction of movement.
[0037] Specifically, the front ends of the middle rigid plate 2 are hingedly connected to the rear ends of the front rigid plate 1. In this embodiment, the front of the middle rigid plate 2 is provided with two first hinge holes 11, and the rear of the front rigid plate 1 is provided with two second hinge holes 12. The two first hinge holes 11 and the two second hinge holes 12 correspond to each other and their axes coincide. The corresponding first hinge holes 11 and second hinge holes 12 are connected by a hinge pin 9. The hinge pin 9 is inserted into the first hinge hole 11 and the second hinge hole 12, allowing the middle rigid plate 2 to rotate about the hinge pin 9.
[0038] The first limiting mechanism 4 is disposed at the rear portion of the front rigid plate 1 and includes a limiting plate 15. The limiting plate 15 is fixed to the front surface of the front rigid plate 1 and extends rearward to the front surface of the rear portion of the middle rigid plate 2. The limiting plate 15 contacts the front surface of the rear portion of the middle rigid plate 2 to limit the outward rotation of the middle rigid plate 2.
[0039] The shape of the middle rigid plate 2 is approximately cross-shaped, and mainly includes a connected vertical connecting plate 13 and a horizontal connecting plate 14, wherein the front side of the vertical connecting plate 13 is rotatably connected to the rear side of the front rigid plate 1, and the rear end of the limiting plate 15 contacts the front side of the front rigid plate 1 for limiting.
[0040] In order to make the vertical connection plate 13 rotate more smoothly, a second flexible plate 8 is provided on the back of the front rigid plate 1, and the second flexible plate 8 is connected to the vertical connection plate 13. The first flexible plate 10 and the second flexible plate 8 can generally be made of flexible films.
[0041] The middle portion of the first flexible plate 10 is fixedly connected to the transverse connecting plate 14. The upper and lower portions of the first flexible plate 10 are respectively connected to the two pectoral fin rigid plates 3, forming two gaps 6 between the transverse connecting plate 14 and the two pectoral fin rigid plates 3. The bottom surface of the upper pectoral fin rigid plate 3 and the top surface of the lower pectoral fin rigid plate 3 are respectively parallel to the top and bottom surfaces of the transverse connecting plate 14, and the gaps 6 are rectangular gaps 6. Preferably, the two pectoral fin rigid plates 3 are arranged symmetrically with respect to the transverse connecting plate 14.
[0042] The second limiting mechanism 5 includes a fixed limiting block 16 and two movable limiting blocks 17. The fixed limiting block 16 is fixed to the front of the transverse connecting plate 14. The width of the fixed limiting block 16 is greater than the width of the transverse connecting plate 14. The upper and lower ends of the fixed limiting block 16 extend out of the transverse connecting plate 14. The two movable limiting blocks 17 are respectively fixed to the front of the two pectoral fin rigid plates 3. The end of the movable limiting block 17 close to the gap 6 extends out of the pectoral fin rigid plate 3. The top and bottom surfaces of the fixed limiting block 16 are in contact with the two movable limiting blocks 17 respectively, and the contact seam is located in the two gaps 6. The movement of the pectoral fin rigid plate 3 can drive the movable limiting block 17 to move. The fixed limiting block 16 and the movable limiting block 17 offset each other to limit the outward rotation of the pectoral fin rigid plate 3, so that the pectoral fin rigid plate 3 can only rotate inward.
[0043] The number of the second limiting mechanisms 5 can be multiple, and the multiple second limiting mechanisms 5 are arranged at intervals along the length direction of the transverse connecting plate 14 .
[0044] It should be noted that the shapes of the fixed limit block 16 and the movable limit block 17 can be flexibly set according to the actual application scenario. It is only necessary to ensure that the contact surfaces of the fixed limit block 16 and the movable limit block 17 are in contact with each other to achieve the limiting function. For example, in this embodiment, the fixed limit block 16 and the movable limit block 17 are both rectangular blocks, and the two movable limit blocks 17 are symmetrically arranged with respect to the fixed limit block 16.
[0045] When the multi-jointed pectoral fin with high drag reduction is applied to a bionic robotic fish, the back of the pectoral fin should face the power stroke end, and the front of the pectoral fin should face the recovery stroke end. The process of the power stroke and the recovery stroke is as follows:
[0046] Power stroke: Figure 4 and 5 As shown, the front rigid plate 1 is driven to rotate so as to approach the fish body, and the resistance of the water pushes the middle rigid plate 2 and the two pectoral fin rigid plates 3 outward. Under the limiting action of the first limiting mechanism 4, the middle rigid plate 2 cannot rotate relative to the front rigid plate 1, and under the limiting action of the second limiting mechanism 5, the two pectoral fin rigid plates 3 cannot rotate relative to the transverse connecting plate 14. The two pectoral fin rigid plates 3 are fully unfolded, so that the pectoral fin area is maximized, so that the pectoral fin can maintain the specified movement of the motor during the power stroke.
[0047] Recovery stroke: Figure 6 and 7As shown, the front rigid plate 1 is driven to rotate away from the fish body, and the resistance of the water pushes the middle rigid plate 2 and the two pectoral fin rigid plates 3 inward, and the limiting effect of the first limiting mechanism 4 disappears. The middle rigid plate 2 rotates inward relative to the front rigid plate 1 to generate bending, and the second flexible plate 8 generates adaptive bending. At the same time, the limiting effect of the second limiting mechanism 5 disappears, and the two pectoral fin rigid plates 3 rotate inward relative to the transverse connecting plate 14 to generate bending, so that the two pectoral fin rigid plates 3 are folded, so that the area of the pectoral fin is minimized during the recovery stroke.
[0048] In this highly efficient drag-reducing multi-jointed pectoral fin, the pectoral fin rigid plates 3 are fully extended during the power stroke, maximizing the pectoral fin area and generating greater thrust. During the recovery stroke, the pectoral fin rigid plates 3 are relatively folded, minimizing the pectoral fin area, reducing drag on the pectoral fin and thereby increasing the net thrust during the pectoral fin flapping process. This allows for highly efficient drag reduction throughout a single fin flapping cycle, thereby improving the performance of the robotic fish.
[0049] In this document, directional terms such as front, back, top, and bottom are defined based on the positions of components in the accompanying drawings and relative to each other, and are intended for clarity and convenience in describing the technical solution. It should be understood that these terms are relative and may vary depending on usage and placement. The use of these directional terms should not limit the scope of protection claimed in this application.
[0050] The above embodiments and features of the embodiments may be combined with each other unless there is a conflict. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.
Claims
1. A multi-jointed pectoral fin with high drag reduction, characterized in that: include: front rigid plate; a middle rigid plate, the front portion of which is rotatably connected to the rear portion of the front rigid plate, and a first limiting mechanism is provided between the middle rigid plate and the front rigid plate to limit the middle rigid plate from rotating only in a predetermined direction of movement, and a first flexible plate is provided on the back of the middle rigid plate; And two pectoral fin rigid plates are respectively connected to the upper and lower parts of the first flexible plate, and a second limiting mechanism is provided between the first flexible plate and the two pectoral fin rigid plates to limit the two pectoral fin rigid plates to move only in a predetermined direction of movement.
2. The multi-jointed pectoral fin with high drag reduction according to claim 1, characterized in that: The two ends of the front portion of the middle rigid plate are respectively hingedly connected to the two ends of the rear portion of the front rigid plate.
3. The multi-jointed pectoral fin with high drag reduction according to claim 2, characterized in that: Two first hinge holes are provided at the front of the middle rigid plate, and two second hinge holes are provided at the rear of the front rigid plate. The two first hinge holes and the two second hinge holes correspond to each other one by one and their axes coincide with each other. The corresponding first hinge holes and the second hinge holes are connected by a hinge pin.
4. The multi-jointed pectoral fin with high drag reduction according to claim 1, characterized in that: The first limiting mechanism includes a limiting plate, which is fixed to the front surface of the front rigid plate and extends backward to the front surface of the rear portion of the middle rigid plate.
5. The multi-jointed pectoral fin with high drag reduction according to claim 1, characterized in that: The middle rigid plate comprises a vertical connecting plate and a horizontal connecting plate connected to each other, wherein the front side of the vertical connecting plate is rotatably connected to the rear side of the front rigid plate.
6. The multi-jointed pectoral fin with high drag reduction according to claim 5, characterized in that: The middle portion of the first flexible plate is fixedly connected to the transverse connecting plate, and the upper portion and the lower portion of the first flexible plate are respectively connected to the two pectoral fin rigid plates, so that two gaps are formed between the transverse connecting plate and the two pectoral fin rigid plates.
7. The multi-jointed pectoral fin with high drag reduction according to claim 6, characterized in that: The second limiting mechanism includes a fixed limiting block and two movable limiting blocks, the fixed limiting block is fixed to the front face of the transverse connecting plate, the two movable limiting blocks are respectively fixed to the front faces of the two pectoral fin rigid plates, the top surface and bottom surface of the fixed limiting block are respectively in contact with the two movable limiting blocks, and the contact seam is located in the two gaps.
8. The multi-jointed pectoral fin with high drag reduction according to claim 7, characterized in that: The fixed limiting block and the movable limiting block are both rectangular blocks, and the two movable limiting blocks are symmetrically arranged with respect to the fixed limiting block.
9. The multi-jointed pectoral fin with high drag reduction according to claim 5, characterized in that: A second flexible board is provided on the back side of the front rigid board, and the second flexible board is connected to the vertical connection board.
10. The multi-jointed pectoral fin with high drag reduction according to claim 9, characterized in that: The first flexible board and the second flexible board are both flexible films.